Not applicable.
1. Field of the Invention
The present invention relates generally to disk drives, and in particular to an air bearing slider which includes an angularly disposed channel formed between a side rail and a leading side air bearing surface.
2. Description of the Prior Art
The typical hard disk drive includes a head disk assembly (HDA) and a printed circuit board assembly (PCBA) attached to a disk drive base of the HDA. The head disk assembly includes the disk drive base, a cover, at least one magnetic disk, a spindle motor for rotating the disk, and a head stack assembly (HSA).
The spindle motor includes a spindle motor hub that is rotatably attached to the disk drive base. The spindle motor hub has an outer hub flange that supports a lowermost one of the disks. Additional disks may be stacked and separated with annular disk spacers that are disposed about the spindle motor hub. The head stack assembly has an actuator assembly including at least one air bearing slider or head, typically several, for reading and writing data from and to the disk. Each air bearing slider includes a magnetic transducer. An example of a slider is disclosed in U.S. Pat. No. 5,777,825 (incorporated herein by reference) that describes a slider where a center pad disposed at a trailing side contains a transducer. The printed circuit board assembly includes a servo control system in the form of a disk controller for generating servo control signals. The head stack assembly is controllably positioned in response to the generated servo control signals from the disk controller. In so doing, the attached sliders are moved relative to tracks disposed upon the disk.
The head stack assembly includes the actuator assembly, at least one head gimbal assembly (HGA), and a flex circuit cable assembly that are attached to the actuator assembly. A conventional xe2x80x9crotaryxe2x80x9d or xe2x80x9cswing-typexe2x80x9d actuator assembly typically comprises an actuator body, a pivot bearing cartridge, a coil portion that extends from one side of the actuator body to interact with one or more permanent magnets to form a voice coil motor, and one or more actuator arms that extend from an opposite side of the actuator body. The actuator body includes a bore and the pivot bearing cartridge engaged within the bore for allowing the actuator body to rotate between limited positions. At least one head gimbal assembly is distally attached to each of the actuator arms. A head gimbal assembly includes an air bearing slider that is attached to a suspension with a gimbal. The suspension resiliently supports the slider above the tracks of the disk during operation of the disk drive facilitating the slider to xe2x80x9cflyxe2x80x9d above the disk. The head gimbal assemblies and the flex circuit cable assembly are attached to the actuator assembly. The actuator assembly is controllably rotated so as to move the sliders relative to the disks for reading and writing operations with respect to the tracks contained on the disks.
A typical slider design includes leading and trailing sides. A center pad that includes an air bearing surface is disposed adjacent the trailing edge. A transducer is embedded within the center pad. At least one additional air bearing surface disposed upon a pad is provided adjacent the leading side. In this regard, a single air bearing surface may be provided which extends the width of the slider. Alternatively, a pair of air bearing surfaces may be provided at opposite lateral sides of the slider adjacent the leading edge. In addition, a depressed region or cavity is centrally disposed between the center pad and the leading side air bearing surfaces. Furthermore, lateral pad or side rails may be disposed laterally with respect to the slider for providing aerodynamic stability, especially with respect to roll stability.
In order to increase the amount of data recorded upon a given disk, specifications for increasing areal density continue to increase. As a result, it is desirable to fly the slider at lower and lower heights above the tracks of the disks. However, lower fly heights increase the susceptibility of the slider coming into physical contact with the disk during operation. Such contact or xe2x80x9ccrashxe2x80x9d may result in damage to the slider, including the transducer therein, as well as the disk and the data associated with the tracks.
The various tracks recorded on the disk form an annular data region across the disk. Non-data regions are typically disposed at the ID radius and OD radius of the disk. In one configuration, the head stack assembly is configured to pivot the actuator assembly such that the sliders are positioned or parked on a ramp overlying a portion of a non-data region, such as at the OD radius, when the disk drive is not performing disk reading or writing operations. In such a configuration, during loading and unloading operations, the sliders may be subject to a variety of forces that may result in the sliders coming into contact with the disk at the adjacent non-data region. Accordingly, there is a need in the art for an improved slider in comparison to the prior art.
An aspect of the present invention can be regarded as the air bearing slider for use in a disk drive. The slider includes a leading side and an opposing trailing side. The slider further includes a pair of opposing lateral sides disposed between the leading and trailing sides. The slider further includes a leading side air bearing surface. The leading side air bearing surface includes a main portion adjacent the leading side and a trailing portion extending from the main portion toward the trailing side along a respective one of the lateral sides. The slider further includes a side rail disposed laterally along and between the respective lateral side and the trailing portion. The slider further includes a channel formed between the side rail and the trailing portion disposed angularly with respect to the respective lateral side by extending from adjacent the respective lateral side towards the trailing side away from the respective lateral side for receiving airflow through the channel during operation of the disk drive.
According to various embodiments, the side rail may be tapered towards the leading side. The trailing portion may be tapered towards the trailing side. The side rail may include a side rail air bearing surface disposed toward the trailing side, and a side rail shallow recessed surface extending away from the side rail air bearing surface laterally along and between the respective lateral side and the trailing portion. The side rail shallow recessed surface may be tapered toward the leading side. The side rail air bearing surface may include a leading edge angularly disposed with respect to the opposing lateral sides. The leading edge of the side rail air bearing surface is disposed substantially perpendicular with respect to the channel. The slider may further include a deep recessed surface disposed between the leading and trailing sides. The deep recessed surface may extend into the channel. The channel may be disposed at an angle of between 10 to 20 degrees with respect to the respective lateral side. The slider may further include a trailing side pad including a transducer disposed adjacent the trailing side. The trailing side pad may include a trailing side air bearing surface disposed adjacent the trailing side. The trailing side pad may include a trailing side shallow recessed surface extending towards the leading side from the trailing side air bearing surface. The trailing side air bearing surface may include a leading edge angularly disposed with respect to the opposing lateral sides. The leading edge of the trailing side air bearing surface may be disposed substantially perpendicular with respect to the channel. The side rail may be a first side rail, and the slider may further include a second side rail disposed adjacent the other respective one of the opposing lateral sides. The trailing portion may be a first trailing portion, and the leading side air bearing surface may further include a second trailing portion extending from the main portion toward the trailing side along the other respective lateral side. The second trailing portion may be disposed laterally along and between the second side rail and the other respective lateral side. The channel may be a first channel, and the slider may further include a second channel formed between the second trailing portion and the second side rail disposed angularly with respect to the other respective lateral side by extending from adjacent the other respective lateral side towards the leading side away from the other respective lateral side for receiving airflow through the second channel during operation of the disk drive.
According to another aspect of the present invention, there is provided a disk drive including a disk drive housing and a head stack assembly rotatably coupled to the disk drive housing. The head stack assembly includes an air bearing slider in its various embodiments as discussed above.